/*
 * Copyright (c) 2010-2018 Nathan Rajlich
 *
 *  Permission is hereby granted, free of charge, to any person
 *  obtaining a copy of this software and associated documentation
 *  files (the "Software"), to deal in the Software without
 *  restriction, including without limitation the rights to use,
 *  copy, modify, merge, publish, distribute, sublicense, and/or sell
 *  copies of the Software, and to permit persons to whom the
 *  Software is furnished to do so, subject to the following
 *  conditions:
 *
 *  The above copyright notice and this permission notice shall be
 *  included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 *  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 *  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 *  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *  OTHER DEALINGS IN THE SOFTWARE.
 */

package com.alipay.api.java_websocket;

import com.alipay.api.java_websocket.enums.Role;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ByteChannel;

public class SocketChannelIOHelper {

    public static boolean read(final ByteBuffer buf, WebSocketImpl ws, ByteChannel channel) throws IOException {
        buf.clear();
        int read = channel.read(buf);
        buf.flip();

        if (read == -1) {
            ws.eot();
            return false;
        }
        return read != 0;
    }

    /**
     * @param buf     The ByteBuffer to read from
     * @param ws      The WebSocketImpl associated with the channels
     * @param channel The channel to read from
     * @return returns Whether there is more data left which can be obtained via {@link WrappedByteChannel#readMore(ByteBuffer)}
     * @throws IOException May be thrown by {@link WrappedByteChannel#readMore(ByteBuffer)}#
     * @see WrappedByteChannel#readMore(ByteBuffer)
     **/
    public static boolean readMore(final ByteBuffer buf, WebSocketImpl ws, WrappedByteChannel channel) throws IOException {
        buf.clear();
        int read = channel.readMore(buf);
        buf.flip();

        if (read == -1) {
            ws.eot();
            return false;
        }
        return channel.isNeedRead();
    }

    /**
     * Returns whether the whole outQueue has been flushed
     *
     * @param ws          The WebSocketImpl associated with the channels
     * @param sockchannel The channel to write to
     * @return returns Whether there is more data to write
     * @throws IOException May be thrown by {@link WrappedByteChannel#writeMore()}
     */
    public static boolean batch(WebSocketImpl ws, ByteChannel sockchannel) throws IOException {
        if (ws == null) {
            return false;
        }
        ByteBuffer buffer = ws.outQueue.peek();
        WrappedByteChannel c = null;

        if (buffer == null) {
            if (sockchannel instanceof WrappedByteChannel) {
                c = (WrappedByteChannel) sockchannel;
                if (c.isNeedWrite()) {
                    c.writeMore();
                }
            }
        } else {
            do {// FIXME writing as much as possible is unfair!!
                /*int written = */
                sockchannel.write(buffer);
                if (buffer.remaining() > 0) {
                    return false;
                } else {
                    ws.outQueue.poll(); // Buffer finished. Remove it.
                    buffer = ws.outQueue.peek();
                }
            } while (buffer != null);
        }

        if (ws.outQueue.isEmpty() && ws.isFlushAndClose() && ws.getDraft() != null && ws.getDraft().getRole() != null
                && ws.getDraft().getRole() == Role.SERVER) {//
            ws.closeConnection();
        }
        return c == null || !((WrappedByteChannel) sockchannel).isNeedWrite();
    }
}
